1. Field of the Invention
The invention relates to a connection device and, in particular, to a multi-serial connection device and a connection card thereof.
2. Description of Related Art
A serial connector refers to a serial communication port. The prefix ‘multi’ here refers to the Component Object Model (COM) interface, which is the specification for currently existing multiple serial signaling interfaces, such as RS232, RS422 and RS485. The serial connectors are roughly classified according to the number of contacts into the D-type 9-pin serial port (DB9) and D-type 25-pin serial port (DB25). However, with the trend of computer miniaturization, as shown in FIG. 6, most computer manufacturers tend to use the Universal Serial Bus (USB) connector 72 (supporting serial signal transmissions) or Mini DisplayPort connector 73 (supporting audio/video signal transmissions) that is even smaller than the DB9 connector 71. Since the USB connector is also a serial communication interface, there is a low probability that future computers will use DB9 or DB25 as the standard interface. They will have to face the fate of being eliminated.
The DB9 standard has been popular for many years, and is commonly seen in industrial automation and business automation electronic devices. Such electronic devices are usually controlled or managed by computers and communicate with each other through the DB9 standard. Therefore, if computers no longer support DB9 connectors, great inconvenience will inevitably be resulted for the control or management of these electronic devices in the future. It is thus imperative to improve the multi-serial port connectors.